Despite advances in basic neurosciences, movement disorders continue to represent a considerable medical challenge. Mechanisms for these disorders are only speculative and diagnostic categories poorly defined. Accordingly, therapies are infrequently effective, and when effective, poorly understood. Research necessarily must be conducted to improve diagnostic and classification systems and scientifically identify the parameters of therapeutic effectiveness. In this project we propose to extend our preliminary research on behavioral and electromyographic assessment of pharmacological treatments for patients with movement disorders. Specifically, we propose to: l) scientifically evaluate a methodology for assessing treatments of movement disorder; 2) correlate this assessment methodology with electrophysiological measures of muscle activity during specific motor tasks; and, 3) employ this assessment methodology and corresponding molecular measures to investigate specific drug therapies for two movement disorders, choreoathetoid cerebral palsy and dystonia. This research, utilizing a behavioral medicine methodology, will provide important contributions to the understanding of movement disorders, and will formalize assessment methodology for continuing clinical research on pharmacological and other types of treatment.